Reciprocating compressor

ABSTRACT

A reciprocating compressor is disclosed which has a valve construction using plural discharge ports, plural reed valves and plural valve backers to lower the discharge resistance and improve the compression efficiency. The reciprocating compressor ( 1000 ) has within a closed vessel ( 900 ) a reciprocating compressing section ( 300 ) for compressing a required fluid, the reciprocating compressing section ( 300 ) comprising a discharge unit for discharging the fluid and a valve assembly ( 500 ) for opening and closing the discharge unit, with a plurality of discharge ports ( 522 A,  522 B) being formed in the valve assembly, the valve assembly ( 500 ) comprising valve members ( 560 ), the valve members ( 560 ) comprising reed valves ( 530 A,  530 B) disposed correspondingly to the discharge ports ( 522 A,  522 B) and valve backers ( 540 A,  540 B) disposed respectively on back sides of the reed valves, a valve seat ( 520 ) having a recess for receiving the valve members therein, and valve members fixing means for urging end sides of the valve members to fix the valve members elastically to fixing portions ( 523 A,  523 B) of the recess.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a reciprocating compressor to be used,for example, for compressing a refrigerant in a home refrigerator.Particularly, the present invention is concerned with an improvement ofa valve assembly portion which is for opening and closing a dischargeunit in a compressing section.

2. Description of the Prior Art

A reciprocating compressor of this type has such a schematicconstruction as FIG. 1 which illustrates a compressor 1000.

In FIG. 1, the compressor 1000 comprises an assembly. According to theconstruction of this assembly, a motor section 200 is driven by electricpower fed from a power dispatching section 100 which supplies electricpower 101. A reciprocating compressing section 300 is connected to themotor section 200 to compress a refrigerant fluid which is introducedfrom an intake path 601 in an intake section 600 through a valveassembly 500. The refrigerant fluid thus compressed is discharged from adischarge path 701 in a discharge section 700. The assembly thusconstructed is mounted and accommodated in the interior of a closedvessel 900 elastically by means of a buffer/support section 800.

Further, there is provided a construction whereby lubricating oil 401stored in the bottom of the closed vessel 900 is circulated forlubrication to a mechanical kinetic portion between the motor section200 and the reciprocating compressing section 300 by means of an oilfeeder 400. Various proposals have been made about concrete structuresof various portions in the above construction of the compressor (seeJapanese Patent Publication No. H04(1992)-4894).

Since a piston reciprocates at a high speed of about 3,000 rpm, variousimprovements have been made in connection with the construction of thevalve assembly 500. For example, there has been proposed a constructionusing a valve assembly, the valve assembly being provided with a thickplate as a restriction piece having an appropriate divergent angle, therestriction piece being disposed on a back side of a reed valve which isfor opening and closing a discharge port, whereby not only the degree ofopening of the reed valve is restricted but also the return speed of thereed valve is increased to improve the compressing efficiency (seeJapanese Utility Model Publication No. H02(1990)-25986).

There also has been proposed a construction using a valve assemblywherein a reed valve and a plate spring as a restriction piecesuperimposed on a back side of the reed valve are disposed within arecess of a valve seat, and about half of a portion which covers adischarge port of the reed valve is covered with the restriction piece,whereby the reed valve opens while having a twisted surface, a fluiddischarge direction is set toward an outlet by the twisted surface, andthe closing speed is increased by a return stress of twist (see U.S.Pat. No. 4,723,896).

However, all of the above conventional valve assemblies adopt a valveconstruction comprising one discharge port, one reed valve for openingand closing the discharge port, and one restriction piece disposed onthe back side of the reed valve. Therefore, in a compressor providedwith such a valve assembly, the discharge resistance is still high,resulting in a lowering of the compression efficiency, and thus therehas been room for improvement.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a reciprocatingcompressor using a valve construction provided with plural dischargeports, reed valves and restriction/repulsion pieces (hereinafterreferred to as “valve backers”), thereby decreasing the dischargeresistance and improving the compression efficiency.

For achieving the above-mentioned object, in one aspect of the presentinvention there is provided a reciprocating compressor having within aclosed vessel a reciprocating compressing section for compressing arequired fluid, the reciprocating compressing section comprising adischarge unit for discharging the fluid and a valve assembly foropening and closing the discharge unit, with a plurality of dischargeports being formed in the valve assembly, the valve assembly comprisingvalve members, the valve members comprising reed valves disposedcorrespondingly to the discharge ports and valve backers disposedrespectively on back sides of the reed valves, a valve seat having arecess for receiving the valve members therein, and valve members fixingmeans for urging end sides of the valve members to fix the valve memberselastically to fixing portions of the recess.

In a second aspect of the present invention there is provided, incombination with the above first aspect, a reciprocating compressorwherein the reed valves are each formed in a shape comprising fulcrumportions projecting to both sides in the associated one of the fixingportions, an intermediate portion projecting in a perpendicular oroblique direction with respect to a line joining the fulcrum portions,and a lid portion for closing the associated one of the discharge ports,the lid portion lying on the side opposite to the fulcrum portions withrespect to the intermediate portion, the fulcrum portions, theintermediate portion and the lid portion being integral with oneanother, and the valve backers are each formed in a shape comprising thesame fulcrum portions as those of each of the reed valves, anintermediate portion having a gradually narrowing portion projecting inan oblique direction with respect to a line joining the fulcrumportions, and an opposite end portion narrower than the lid portion ofeach of the reed valves, the fulcrum portions, the intermediate portionand the opposite end portion being integral with one another.

In a third aspect of the present invention there is provided, incombination with the above second aspect, a reciprocating compressorwherein the reed valves are disposed in such a manner that the lidportions of the reed valves are positioned centrally and the fulcrumportions of one of the reed valves and the fulcrum portions of the otherreed valve are positioned outside the lid portions, and the valvebackers are disposed in such a manner that the intermediate portions ofthe valve backers are positioned in directions different from each otherwith respect to the line joining the fulcrum portions.

In a fourth aspect of the present invention there is provided, incombination with the above second or third aspect, a reciprocatingcompressor wherein the valve members fixing means is formed in a shapecomprising fixing portions for fixing the fulcrum portions of the valvemembers to the fixing portions of the recess and a spring portion forconnecting the fixing portions of the valve members fixing means witheach other and for urging the fulcrum portions of the valve memberselastically to the fixing portions of the recess, the fixing portionsand the spring portion being integral with each other.

Thus, the reciprocating compressor in the above first aspect of thepresent invention has within a closed vessel a reciprocating compressingsection for compressing a required fluid, the reciprocating compressingsection comprising a discharge unit for discharging the fluid and avalve assembly for opening and closing the discharge unit, with aplurality of discharge ports being formed in the valve assembly, thevalve assembly comprising valve members, the valve members comprisingreed valves disposed correspondingly to the discharge ports and valvebackers disposed respectively on back sides of the reed valves, a valveseat having a recess for receiving the valve members therein, and valvemembers fixing means for urging end sides of the valve members to fixthe valve members elastically to fixing portions of the recess.

With the valve members fixing means, the valve members can be fixedelastically to the fixing portions of the recess. Moreover, with theelasticity of the valve backers, restriction and repulsive return of thereed valves are performed to afford an effect of enhancing theefficiency of a pressurizing operation. Further, since the valveassembly adopted uses a valve construction provided with pluraldischarge ports and also provided correspondingly with reed valves andvalve backers, there is attained an outstanding effect such that it ispossible to lower the discharge resistance and improve the compressionefficiency.

According to the reciprocating compressor in the above second aspect ofthe present invention, in combination with the above first aspect, thereed valves are each formed in a shape comprising fulcrum portionsprojecting to both sides in the associated one of the fixing portions,an intermediate portion projecting in a perpendicular or obliquedirection with respect to a line joining the fulcrum portions, and a lidportion for closing the associated one of the discharge ports, the lidportion lying on the side opposite to the fulcrum portions with respectto the intermediate portion, the fulcrum portions, the intermediateportion and the lid portion being integral with one another, and thevalve backers are each formed in a shape comprising the same fulcrumportions as those of each of the reed valves, an intermediate portionhaving a gradually narrowing portion projecting in an oblique directionwith respect to a line joining the fulcrum portions, and an opposite endportion narrower than the lid portion of each of the reed valves, thefulcrum portions, the intermediate portion and the opposite end portionbeing integral with one another.

By disposing the fulcrum portions in the fixing portions of the recessthrough the valve members fixing means, it is possible to fix the valvemembers easily and positively. Besides, the reed valves when opened caneach be allowed to perform such a motion as the letter S being stretchedobliquely and the head portion twisted. In resistance to such acubically complicated way of bending an internal stress is stored in thereed valves themselves and the valve backers, and with the resultingrepulsive force it is possible to further increase the reed valve returnspeed, thus affording a further outstanding effect that the compressionefficiency can be further improved.

According to the reciprocating compressor in the above third aspect ofthe present invention, in combination with the above second aspect, thereed valves are disposed in such a manner that the lid portions of thereed valves are positioned centrally and the fulcrum portions of one ofthe reed valves and the fulcrum portions of the other reed valve arepositioned outside the lid portions, and the valve backers are disposedin such a manner that the intermediate portions of the valve backers arepositioned in directions different from each other with respect to theline joining the fulcrum portions.

Since the reed valves open while being bent in opposite directions, thecollision of refrigerant gases discharged from the reed valves isdiminished and the discharge resistance is made still lower, thusaffording a further outstanding effect that the compression efficiencycan be further improved.

According to the reciprocating compressor in the above fourth aspect ofthe present invention, in combination with the above second or thirdaspect, the valve members fixing means is formed in a shape comprisingfixing portions for fixing the fulcrum portions of the valve members tothe fixing portions of the recess and a spring portion for connectingthe fixing portions of the valve members fixing means with each otherand for urging the fulcrum portions of the valve members elastically tothe fixing portions of the recess, the fixing portions and the springportion being integral with each other.

There can be obtained a further outstanding effect that the valvemembers can be fixed to the aforesaid recess easily and positively byone valve members fixing means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an entire construction common to botha reciprocating compressor according to an embodiment of the presentinvention and the prior art;

FIG. 2 is a sectional view showing an entire construction of theembodiment of the present invention in an exploded state;

FIG. 3 is a perspective view partly in section, showing an entireconstruction of the embodiment of the present invention in an assembledstate of various constituent portions;

FIG. 4 is an enlarged diagram showing principal portions of FIG. 2 indetail;

FIG. 5 is an explanatory diagram showing an assembled state of variousportions related to a valve assembly used in the embodiment of thepresent invention;

FIG. 6(A) is an explanatory plan view showing an assembled state ofvarious portions related to the valve assembly in the embodiment of thepresent invention, FIG. 6(B) is an explanatory plan view showing indetail principal portions of reed valves and valve backers shown in FIG.6(A), and FIG. 6(C) is an explanatory plan view showing a state in whichvalve backers are disposed on back sides of the reed valvesrespectively;

FIG. 7 is an explanatory sectional view taken on line A-A in FIG. 6(A);and

FIG. 8 is an explanatory diagram showing a state in which a valve backeris disposed on the back side of a reed valve.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

A reciprocating compressor according to an embodiment of the presentinvention will be described in detail hereinunder with reference to theaccompanying drawings.

FIG. 1 is a block diagram showing an entire construction common to botha reciprocating compressor according to an embodiment of the presentinvention, FIG. 2 is a sectional view showing an entire construction ofthe embodiment of the present invention in an exploded state, FIG. 3 isa perspective view partly in section, showing an entire construction inan assembled state of various constituent portions, FIG. 4 is anenlarged diagram showing principal portions of FIG. 2 in detail, FIG. 5is an explanatory diagram showing an assembled state of various portionsrelated to a valve assembly used in the embodiment of the presentinvention, FIG. 6(A) is an explanatory plan view showing an assembledstate of various portions related to the valve assembly in theembodiment of the present invention, FIG. 6(B) is an explanatory planview showing in detail principal portions of reed valves and valvebackers shown in FIG. 6(A), and FIG. 6(C) is an explanatory plan viewshowing a state in which valve backers are disposed on back sides of thereed valves respectively, FIG. 7 is a sectional view taken on line A-Ain FIG. 6(A), and FIG. 8 is an explanatory diagram showing a state inwhich a valve backer is disposed on the back side of a reed valve.

Functional portions represented by reference numerals are assembled bycombinations indicated with fine lines and chain lines and are mountedand fixed or engaged using set screws and retaining springs. In theaccompanying drawings, portions of the same reference numerals representportions having the same functions, and portions of the same referencenumerals as in FIG. 1 represent portions having the same functions asthose of the portions of the same reference numerals illustrated in FIG.1.

In FIGS. 1 to 3, a stator 210, a rotor 220, a rotatable shaft 230 and abearing 240 are assembled together to constitute a motor section 200,which is connected to a power dispatching section 100. A buffer/supportsection 800 is constituted by a helical spring or the like.

A crescent balancing plate 231 is integrally formed at a lower endportion of the rotatable shaft 230 in the motor section 200 and aneccentric pin 310 is disposed on the side opposite to the crescentbalancing plate 231, thereby constituting a motion mechanism for makingthe eccentric pin 310 perform a motion which describes a circular path.

A motion mechanism which is driven by the eccentric pin 310 to create alinear reciprocating motion is constituted within a T-shaped crank tube330, and a piston 340 reciprocates within a cylinder bore of a cylinder350 to effect a compression action. A reciprocating compressing section300 is constituted by the portions from the eccentric pin 310 to thecylinder 350.

A valve assembly 500, which is mounted in contact with the cylinder 350,is mainly composed of a gasket 551, an intake-side valve member 510, avalve seat 520, two reed valves 530, two valve backers 540, valvemembers fixing means 570, and a gasket 550. These portions aresandwiched in between an end face 352 of the cylinder 350 whichconstitutes the reciprocating compressing section 300 and an end face713 of a head muffler member 710 which constitutes a discharge section700, and are then fixed with screws for assembly. Thus, the portions inquestion are held grippingly and fixed between the end face 352 of thecylinder 350 and the muffler member 710 of the discharge section 700.

The reference numeral 600 denotes an intake section. A refrigerant fluidintroduced from an intake path 601 passes through a muffler (not shown)provided with a filter for filtering admixtures, etc. received in aconduit of an object of utilization, further passes through a resonancechamber, and is introduced into the valve assembly 500.

As the solvent used in this embodiment there is used an HFC refrigerant,e.g., R134a.

On the other hand, the refrigerant fluid after compression passesthrough the valve assembly 500 and then through plural mufflers 720having resonance chambers adapted to resonate with a fluid vibration ofa different frequency for deadening a sound, then passes through a pathextending from a discharge pipe (not shown) to a discharge path 701. Inthis way there is constituted a discharge section 700.

After assembly of the above constituent portions, an upper vessel 920 ofa closed vessel 900 is fitted in a lower vessel 910 in a hermeticallysealed state, whereby there is provided an integrated, hermeticallysealed, reciprocating compressor 1000, as shown in FIG. 3. In thisstate, lubricating oil 401 is charged through a charging pipe 402 intothe lower vessel 910. An oil feeder 400 is constituted so as to suck upthe lubricating oil 401 by high-speed rotation of the rotatable shaft230 and circulate it to various constituent portions.

Numeral 360 denotes an intra-case discharge pipe for discharging aportion of the compressed refrigerant into the closed vessel 900 toincrease the internal pressure to a high level.

Next, detailed portions of the valve assembly 500 will be describedbelow with reference to FIGS. 4 to 8.

As shown in FIG. 4, the valve assembly 500, which is mounted in contactwith the cylinder 350, is mainly composed of a gasket 551, anintake-side valve member 510, a valve seat 520, two reed valves 530A,530B, two valve backers 540A, 540B, valve members fixing means 570, anda gasket 550.

These portions are sandwiched in between the end face 352 of thecylinder 350 which constitutes the reciprocating compressing section 300and the end face 713 of the muffler 710 which constitutes the dischargesection 700, and are then fixed with screws and assembled. Further, anintake path extending along an arrow from the right to the left in FIG.4 and a discharge path extending along an arrow from the left to theright in the same figure are formed.

More specifically, there are provided two discharge ports 522A and 522Bfrom which the refrigerant is discharged with a high-speed reciprocatingmotion of the piston 340 within the cylinder 350. The reed valves 530Aand 530B are for opening and closing the discharge ports 522A and 522Band the valve backers 540A and 540B, which are for restriction andrepulsion of openings of the reed valves 530A and 530B, are disposedrespectively on back sides of the reed valves 530A and 530B toconstitute valve members 560. The valve members 560 are received inpredetermined positions (523A, 523B) of a recess 523 formed in the valveseat 520. Thereafter, end sides of the valve members 260 are urged bythe valve members fixing means 570 to fix the valve members elasticallyto predetermined fixing portions (523A, 523B) of the recess 523 (seeFIGS. 5 to 7).

The gasket 551 is interposed between the cylinder 350 and theintake-side valve element 510 and is formed by forming a resin plate,e.g., a fiber-filled butyl rubber plate, into the illustrated shape. Thegasket 551 is provided on its outer periphery with a peripheral edgeportion for closing the peripheral portion between it and the cylinder350, as well as the intake-side valve element 510, and is also providedwith an intake/discharge passage 551A.

The intake-side valve member 510 comprises a reed valve 511, the reedvalve 511 being formed by forming a slit near the center of a planarplate spring, e.g., a stainless steel plate spring having both surfacespolished, and discharge holes 512A and 512B formed outside a baseportion of the reed valve 511, the discharge holes 512A and 512B being alittle larger than the discharge ports 522A and 522B of the valve seat520.

The reed valves 530A and 530B are each formed by forming a planar platespring, e.g., a thin stainless steel plate spring having both surfacespolished, into the illustrated shape. According to this shape, as shownin FIG. 6(B), two fulcrum portions 531 and 532 projecting to both sidesare formed at one end corresponding to a lead valve fixing portion 535,an intermediate portion 533 extends along a center line (y) which isperpendicular to a center line (x) joining the two fulcrums, and a lidportion 534 having a diameter able to close the associated one of thedischarge ports 522A and 522B is formed at an opposite end opposite tothe one end with respect to the intermediate portion 533.

As shown in FIGS. 5 to 7, the reed valves 530A and 530B are disposed inthe predetermined fixing portions (523A, 523B) of the recess 523 in sucha manner that the lid portions 534 of the reed valves 530A and 530B arepositioned centrally, while the fulcrum portions 531 and 532 of one reedvalve 530A and the fulcrum portions 531 and 532 of the other reed valve530B are positioned outside the lid portions 534. The valve backers 540Aand 540B are disposed in such a manner that intermediate portions 543 ofthe valve backers 540A and 540B are positioned in different directionswith respect to lines joining fulcrum portions 541 and 542 of the valvebackers 540A and 540B.

A description will now be given about the valve backer 540A. Accordingto the shape of the valve backer 540A, as shown in FIGS. 6(A) to 6(C),the intermediate portion 543 extends along a center line (z) which isoblique at an angle of θ relative to a center line (y) perpendicular toa center line (x) joining the fulcrum portions 541 and 542, and anopposite end portion 544 is formed on an opposite end side opposite tothe fulcrum portions side with respect to the intermediate portion 543.FIG. 6(C) shows a state in which the valve backers 540A and 540B aredisposed on back sides of the reed valves 530A and 530B respectively.

By so disposing the valve backers 540A and 540B, the reed valves 530Aand 530B are lifted from below and bend in opposite directions and openin the illustrated state by virtue of a discharge pressure.Consequently, the collision between the refrigerant gas discharged fromthe reed valve 530A and that discharged from the reed valve 530B isdiminished, whereby it is possible to further lower the dischargeresistance and improve the compression efficiency.

The valve backers 540A and 540B are each formed by forming a planarplate spring, e.g., a thin stainless steel plate spring having bothsides polished, into the illustrated shape. As is the case with the reedvalves 530A and 530B, two fulcrum portions 541 and 542 projecting toboth sides are formed at one end corresponding to a valve backer fixingportion 549 and an intermediate portion 543 extends in an obliquedirection at a predetermined angle of θ as noted above relative to aline joining the two fulcrums, the intermediate portion 543 extending soas to become narrower gradually from base portions of the fulcrumportions 541 and 542 and form a tip end 544 on the opposite end side,the tip end 544 having a width of about half of the lid portion 534 ineach of the reed valves 530A and 530B. The valve backer fixing portion549 including the fulcrum portions 541 and 542 and the tip end 544 areformed so that their surfaces are parallel to each other, while theintermediate portion 543 is formed in a shape having surfaces curvedalong quadratic curves with a small curvature on a side 543-1 close tothe valve backer fixing portion 549 and a large curvature on a side543-2 close to the tip end 544.

According to this shape of the valve backers 540A and 540B, when thereed valves 530A and 530B are lifted from below in the illustrated stateby virtue of a discharge pressure, they are deformed with elasticdeformation of the valve backers 540A and 540B and along the shape ofthe valve backers. Moreover, the smaller width of the tip end 544permits the reed valves 530A and 530B to be twisted more easily.

The valve members fixing means 570 is formed by forming a thick metallicplate, e.g., a stainless steel plate spring, into the illustrated shapeand is made up of fixing portions 570A and 570B for fixing the fulcrumportions 531, 532, 541 and 542 of the valve members 560 to the fixingportions 523A and 523B of the recess 523 and a spring portion 570C forconnecting the fixing portions 570A and 570B with each other and forurging the fulcrum portions 531, 532, 541 and 542 of the valve members560 elastically to the fixing portions 523A and 523B of the recess 523,the fixing portions 570A, 570B and the spring portion 570C beingintegral with each other.

The fixing portions 570A and 570B of the valve members fixing means 570are mounted from above the fulcrum portions 531, 532, 541 and 542 to thefixing portions 523A and 523B of the recess 523. In this way the valvemembers 560 can be fixed easily and positively by one valve membersfixing means 570.

In this state, the valve assembly 500 is sandwiched and fixed betweenthe end face 352 of the cylinder 350 and the head muffler member 710 inthe discharge section 700, whereby the valve members 560 are preventedfrom dislodgment under vibration or the like.

The valve seat 520 is formed by forming a rather thick metallic plate,e.g., a stainless steel plate into the illustrated shape, which is inconformity with the profile of the fulcrum portions 531 and 532 of thereed valves 530A and 530B. According to the shape of the valve seat 520there is formed a recess 523, the recess 523 comprising fixing portions523A and 523B as a first recess in which the fulcrum portions 531, 532,541, 542 of the reed valves 530A, 530B and the valve backers 540A, 540Benter in a mutually superimposed state and a second recess in which theother portions than the fulcrum portions of the reed valves 530A, 530Band the valve backers 540A, 540B enter, the first and the second recessbeing contiguous to each other. Further, discharge ports 522A and 522Bare formed in the second recess in positions corresponding to the lidportions 534 of the reed valves 530A and 530B.

In the valve seat 520, the recess 523 is formed by stamping and bothsurfaces thereof are finished by polishing. The discharge ports 522A and522B are formed with peripheral rib-like faces 522C, which are finishedby polishing to form contact faces for the reed valves 530A and 530B.Further, an intake port 521 is formed in the planar portion free of therecess 523 in a position corresponding to the reed valve 511 of theintake-side valve member 510.

The gasket 550 is interposed between the valve seat 520 and the headmuffler member 710 in the discharge section 700 and it is formed byforming a resin plate, e.g., a fiber-filled butyl rubber plate, into theillustrated shape. The gasket 550 is provided with a peripheral edgeportion for closing the peripheral portion between the valve seat 520and the head muffler member 710 and is also provided with a partitioningportion 554 for partition between an intake-side small chamber 558 and adischarge-side small chamber 559.

The head muffler member 710 in the discharge section 700 is formed byforming a rather thick metallic plate, e.g., a stainless steel plate,into the illustrated shape, in which a hole as a passage (not shown)leading to the discharge path 701 is formed.

The above constituent elements, that is, all of the gasket 551,intake-side valve member 510, valve seat 520, reed valves 530A, 530B,valve backers 540A, 540B, valve members fixing means 570, gasket 550,and head muffler member 710, are demagnetized to prevent mutual tackingin operation.

As shown in FIG. 6(A), the valve seat 520, the reed valve 530A (530B),and the valve backer 540A (540B), when assembled, are superimposed oneon another in plan.

In the section of FIG. 6(A), that is, in a longitudinal section takenalong the center of the reed valve 530A and that of the reed valve 530B,principal portions are as shown in FIG. 7. In the section of FIG. 6(A)taken on line A-A, the shape of the reed valves 530A, 530B and that ofthe valve backers 540A, 540B are in a pressure-free state. Further, inthe valve members 560 constituted by the reed valves 530A, 530B and thevalve backers 540A, 540B, the reed valve fixing portions 535 and thevalve backer fixing portions 549 at one ends including the fulcrumportions 531, 532, 541 and 542 are held down by the valve members fixingmeans 570.

Since the valve backers 540A and 540B are disposed in the illustratedfashion, when the compressed fluid is discharged from the dischargeports 522A and 522B and a discharge pressure is imposed on the reedvalves 530A and 530B, the reed valves are lifted from below in theillustrated state by virtue of the discharge pressure and exhibit acomplicated way of bending in opposite directions.

This bending is a three-dimensionally complicated way of bending as if acobra raised it head and twisted its neck, that is, a way of bending asif the letter S were drawn out thinly and the head thereof twisted.Consequently, an internal stress resistive to the bending is stored inthe reed valves 530A, 530B and the valve backers 540A, 540B.

When a change is made from the discharge pressure to a counter pressurein this state, a restoring force which acts to correct the bending ofthe reed valves 530A, 530B and close the discharge ports 522A, 522Bappears as a strong repulsive force due to the internal stress againstthe foregoing three-dimensionally complicated way of bending and acts asa force to straighten the foregoing S-bend. Consequently, the reedvalves 530A and 530B perform such an abrupt operation as their tipportions, i.e., lid portions 534 are thrown against the discharge ports522A and 522B. As a result, the reed valves 530A and 530B close thedischarge ports 522A and 522B earlier than the counter pressure andoperate so that the amount of the fluid returning to the discharge ports522A and 522B under the counter pressure can be diminished to theextreme degree.

Thus, in such a closed type reciprocating compressor 1000, the valvemembers 260 can be fixed to the fixing portions 523A and 523B of therecess 523 easily and positively by the valve members fixing means 570and restriction and repulsive return of the reed valves 530A and 530Bare performed with the elasticity of the valve backers 540A and 540B toafford an effect of enhancing the efficiency of the pressurizingoperation. Further, since the valve assembly 500 is of a valveconstruction including two discharge ports 522A, 522B, two reed valves530A, 530B and two valve backers 540A, 540B, the discharge resistance isfurther lowered and the compression efficiency is improved.Consequently, when the reciprocating compressor 1000 is used as acompressor in a refrigerator, the coefficient of performance in therefrigerator is improved.

The above embodiment is for explaining the present invention and neitherlimits the claimed invention nor restricts the scope of claims. Theconstructions of various constituent portions in the present inventionare not limited to those described in the above embodiment, but variousmodifications may be made within the technical scope described in theclaims.

According to the reciprocating compressor of the present invention, thevalve members can be fixed to the fixing portions of the recess in thevalve seat easily and positively by one valve members fixing means.Besides, restriction and repulsive return of the reed valves areperformed with the elasticity of the valve backers to afford an effectof enhancing the efficiency of the pressurizing operation. Moreover,since the valve assembly used a valve construction provided with pluraldischarge ports, plural reed valves and plural valve backers, thedischarge resistance is further lowered and the compression efficiencyis improved. When the reciprocating compressor is used as a compressorin a refrigerator, there is obtained an outstanding effect that thecoefficient of performance in the refrigerator is improved. Thus, thereciprocating compressor of the present invention is high in itsindustrial utility.

1. A reciprocating compressor having within a closed vessel areciprocating compressing section for compressing a required fluid, saidreciprocating compressing section comprising a discharge unit fordischarging said fluid and a valve assembly for opening and closing saiddischarge unit, with a plurality of discharge ports being formed in saidvalve assembly, said valve assembly comprising valve members, said valvemembers comprising reed valves disposed correspondingly to saiddischarge ports and valve backers disposed respectively on back sides ofsaid reed valves, a valve seat having a recess for receiving said valvemembers therein, and valve members fixing means for urging end sides ofsaid valve members to fix said valve members elastically to fixingportions of said recess.
 2. The reciprocating compressor according toclaim 1, wherein: said reed valves are each formed in a shape comprisingfulcrum portions projecting to both sides in the associated one of saidfixing portions, an intermediate portion projecting in a perpendicularor oblique direction with respect to a line joining said fulcrumportions, and a lid portion for closing the associated one of saiddischarge ports, said lid portion lying on the side opposite to saidfulcrum portions with respect to said intermediate portion, said fulcrumportions, said intermediate portion and said lid portion being integralwith one another, and said valve backers are each formed in a shapecomprising the same fulcrum portions as those of each said reed valve,an intermediate portion having a gradually narrowing portion projectingin an oblique direction with respect to a line joining said fulcrumportions, and an opposite end portion narrower than said lid portion ofeach said reed valve, said fulcrum portions, said intermediate portionand said opposite end portion being integral with one another.
 3. Thereciprocating compressor according to claim 2, wherein said reed valvesare disposed in such a manner that said lid portions of said reed valvesare positioned centrally and said fulcrum portions of one of said reedvalves and said fulcrum portions of the other reed valve are positionedoutside said lid portions, and said valve backers are disposed in such amanner that said intermediate portions of said valve backers arepositioned in directions different from each other with respect to saidline joining said fulcrum portions.
 4. The reciprocating compressoraccording to claim 2, wherein said valve members fixing means is formedin a shape comprising fixing portions for fixing said fulcrum portionsof said valve members to said fixing portions of said recess and aspring portion for connecting said fixing portions of said valve membersfixing means with each other and for urging said fulcrum portions ofsaid valve members elastically to said fixing portions of said recess,said fixing portions and said spring portion being integral with eachother.
 5. The reciprocating compressor according to claim 3, whereinsaid valve members fixing means is formed in a shape comprising fixingportions for fixing said fulcrum portions of said valve members to saidfixing portions of said recess and a spring portion for connecting saidfixing portions of said valve members fixing means with each other andfor urging said fulcrum portions of said valve members elastically tosaid fixing portions of said recess, said fixing portions and saidspring portion being integral with each other.